Water Softening Systems: What Every Homeowner Should Know

Have you ever noticed a white scale on your shower walls, the inside glass of your aquarium, or on the edges of your kitchen faucet or shower head? Have you ever noticed how hard that scale is to wash off? Now imagine the same deposits on the insides of every water pipe in the house, building slowly over time until the pipes are completely clogged, and you’ll understand the importance of softening your hard water.

The scale comes from deposits of calcium and magnesium suspended in what is called “hard water.” The more of these chemicals there are in the water, the harder it’s considered to be. A water softening system replaces those two chemicals with salt, which leaves you with water that feels softer than normal and water that won’t clog pipes over time. Water softening systems are known to increase the life span of all of your water-reliant household appliances.

How does a water softener work?

Aquasana Water Softening system.

A good water softener system contains a small tank within (or next to) a larger one. The small tank has a resin inside that draws calcium and magnesium out of the water and holds it. The larger tank contains salt, which is mixed with water and used to regenerate the resin.

A system is timed to flush itself on a regular basis, first sending water backwards through the resin tank to wash out dirt, then pulling in brine (water mixed with salt) from the big tank to wash out the collected chemicals and send them out the drain. The system finishes by flushing out the excess brine with water, so the small tank is left with clean resin that has a few salt crystals attached and is ready to work again.

The diagram below shows how the ion exchange process, itself, works. Hard water flows into the small tank and over the resin – made of tiny polystyrene beads that are negatively charged. As the water passes over and through the beads, any salt (Na2+) attached to the resin lets go and the calcium (Ca2) and magnesium (Mg2) grab on. The water flows on out of the chamber without the two hard chemicals, but now with salt floating in it, making the water much softer than it was.

Diagram of Ion Exchange

Is your water hard or soft?

The amount of calcium and magnesium (i.e. mineral salts) in your water determine how hard or soft it is. These minerals enter the water supply when rainwater washes over the earth or moves through the aquifer, pulling excess mineral salts out of the earth as it flows. Many of these salts have been deposited by the overuse of fertilizers. (Note how the locations in the map below match up with commercial farming regions.)
The following chart shows how many grains per gallon are contained by various qualities of water. The map after that shows the general hardness levels of water throughout the continental United States.
These tools will give you an idea as to whether or not you could benefit from installing a water softener system for your home.

Hardness of Water across the country.

Hardness Magnitude

Grains per Gallon (gpg)

Soft Water

0.0 – 1.0 gpg

Moderately Hard Water

1.0 – 3.5 gpg

Hard Water

3.5 – 7.0 gpg

Very Hard Water

7.0 – 10.5 gpg

Extremely hard water

> 10.5 gpg

What does water softener salt remove?

Clean, soft water does not leave spots, mineral deposits, or rough dry skin behind, the way hard water does. It protects the piping inside your water-using appliances from corrosion (iron, coffee maker, dishwasher, shower heads, etc). It requires the use of less soap, so you save a little money there. And it treats your skin gently, like ocean water does.

Health-wise, the process does add salt to your diet, but not as much as one would expect – normally only about 113.7 mg per gallon, which equates to about 7.11 mg per glass. This is less than a can of soda (24-48 mg) and almost nothing compared to a piece of bread (100 g). People with hypertension issues, who don’t process sodium well should choose a potassium, rather than sodium salt.

Water softener salt and resin

The resin, itself, is made of little beads of polystyrene that carry a negative charge. The negative charge attracts positively charged salt ions, and the more strongly charged calcium and magnesium deposits found in hard water.

There are four different kinds of salt commonly used to soften water: Rock salt, sea salt, evaporated salt, and potassium salts. (Salt crystals and pellets cannot be mixed or used together, without compromising the system.)

Rock salt comes in the form of crystals. It’s mined from the ground in places where deposits have resulted from centuries of soil erosion. The Great Salt Lake in Utah is one such area. This salt usually contains other minerals, which can be left behind in the softening tank, thereby requiring a little more cleaning.

Sea salt (solar salt) comes in the form of pellets. Sea salt is created from seawater left to evaporate on the beach. Harvesters gather the dried salt in baskets and ship it off to be sold in food and other markets. This salt contains trace minerals too, but the kind that our bodies need for good health.

Evaporated salt is collected from the ground and further treated to remove everything except the salt itself. This salt is used in manufacturing companies to remove moisture that would otherwise rust their machines. But “clean” sodium chloride (NaCl) is not as healthy for our bodies as salt that contains trace minerals, like sea salt.

Potassium is a salt often used by those with sodium intake problems. Although a water softener system doesn’t put much salt in the water, some people’s bodies have more of a problem processing it than others and should use potassium instead. Potassium is also a trace mineral that our bodies need, so it’s a healthy choice.

In addition to the salt, itself, some people add hydrogen peroxide to the system to remove harmful microorganisms.

How long does a water softener last?

A good system, well maintained, should last over 20 years. The maintenance required will depend on how hard the water is in your area. Other factors affecting maintenance are the level of iron in your water and the pH level.
Any Horizon Plumbing representative can tell you what a good maintenance schedule would be for you, but here are some tips:
1. Use a higher grade salt to reduce buildup and “bridging” (when salt forms a crust inside the tank, instead collapsing all the way to the bottom).
2. When adding salt, only fill the tank half to three quarters of the way full. Filling it all the way makes the system work harder.
3. If it looks like the salt crystals are packing together, use a broom handle to break them up.
4. Keep a casual eye on your glass shower stall, shower head, or some other place that would normally get spots or calcium deposits. If you start getting them again, the resin may not be working properly. Call your local plumber (if you live in North Texas, reach out to us).
5. Set up the proper size of system for your needs. Too small a system will require maintenance more often.
6. In any case, call your plumber every two years to have the system cleaned. Proper maintenance of water softening systems will increase the shelf life of your system, pipes, and water-dependent appliances).

What size do I need?

The system size will vary, depending on your needs and the size of your household. A mansion will require a larger system than will a small, two bedroom house. And a household of ten or more people will require a larger size than a household of one or two. (Note: water softening systems are NOT intended for landscapes – in fact it is harmful for most plants and turf).